Insects and other terrestrial arthropods make up over half of all described species on earth. Although the majority of these species have no immediate impact on human life, some are extremely important as disease vectors (i.e. tsetse fly, anopeheline mosquitoes, triatomine bugs, ticks ...), and some have developed into agricultural, forest, and household pests. In addition, spiders and their relatives are of particular pharmacological interest because of their ability to synthesize venoms capable of paralyzing their prey. Chemistry plays a central role in the lives of arthropods. The aim of this project is to elucidate arthropod chemistry based on critical, biorational considerations, in ways that should lead to the improvement of human health and welfare. In our experimental approach, we plan on developing the use of NMR spectroscopy for the initial study of bioactive samples obtained from arthropod sources. With the ever-increasing sensitivity of NMR spectrometers, and the remarkable power of multidimensional analytical techniques, it is now realistic to carry out useful NMR analyses even on complex mixtures such as those found in spider venoms, or in whole-insect-body extracts. Specifically, our plans include the search for novel neurotoxins in the venoms of spiders and scorpions; the synthesis of newly-discovered venom components for biological screening; the characterization of a predator-produced kairomone which inhibits mosquito oviposition; a search for new anti-insect agents from insect larvae and pupae; elucidation of the structures of new cardiotonic agents from fireflies. Our overall objectives are (1) to discover the chemical basis for important arthropod interactions, (2) to provide the basis for new control techniques applicable to disease vectors, and (3) to find from arthropod sources new biologically active chemotypes which may serve as lead compounds in drug development or vector control.